During assessment of the interruptions you experience, there will be some pattern of some subjects or some people causing more or longer interruptions.
Regular (say weekly) team briefing meetings, might save time.
You may discover from the interruption assessment, that a particular subordinate or colleague (or even boss) is a prime interrupter. Arrange specific times to see that person and determine methods to reduce the need for interruptions.
Use your diary to make and keep appointments and, if possible, determine periods in which you can't accept phone calls.